There already exists a technology called augmented reality for additional presentation of computer graphics (CG) by superimposing it over a real-world scene. In the augmented reality technology, a transmissive head-mounted display (hereinafter, “HMD”) having a transparent view is used as the display device for presenting information. For example, Published Japanese Translation No. 2009-505268 of the PCT International Application discloses a technology regarding a pair of augmented reality glasses that enables an end-user programmer to view an environment of ambient intelligence having a physical size in such a way that the mechanisms/patterns of virtual interaction (virtual objects) in the environment of ambient intelligence appear superimposed over positions, surfaces, objects, and devices in the real-world environment.
In the technology disclosed in Published Japanese Translation No. 2009-505268 of the PCT International Application, although virtual objects are displayed by superimposition over the real-world space through the transmissive HMD (pair of augmented reality glasses); no consideration is given to the binocular disparity of users. Hence, an image from a single point of view is provided to both the eyes of a user. That leads to a sense of discomfort while viewing real-world objects along with virtual objects thereby spoiling the sense of reality of the virtual objects. Besides, in the technology disclosed in Published Japanese Translation No. 2009-505268 of the PCT International Application, when hands of the user come in between the position of the point of view of the user and the position of placement of a virtual object; the virtual object appears on the hands of the user in a superimposed manner thereby spoiling the sense of reality of that virtual object. Moreover, in the technology disclosed in Published Japanese Translation No. 2009-505268 of the PCT International Application, although a virtual object can be placed at a fixed position within the real-world space, it is not possible to place a virtual object in a moving object such as an automobile that moves within the real-world space.